observe_rsc_update/3

An updated resource is about to be persisted. Observe this notification to change the resource properties before they are persisted.

The props are the resource’s props before the update, but after filtering and sanitization. The folded value is {ok, UpdateProps} for the update itself.

Type:

foldr

Return:

{ok, UpdateProps} or {error, term()}

#rsc_update{} properties:

• action: insert|update
• id: m_rsc:resource_id()
• props: m_rsc:props()

An updated resource is about to be persisted. Observe this notification to change the resource properties before they are persisted.

Arguments

#rsc_update

action

Either insert or update.

id

Id of the resource.

props

Map with resource properties.

{ok, UpdateProps} | {error, Reason}

And/remove resource properties before the update is persisted.

Context

Site context

Example

Add a property before the resource is persisted:

observe_rsc_update(#rsc_update{action = insert, id = Id}, {ok, Props}, Context) ->
    %% Set an extra property
    {ok, Props#{ <<"extra_property">> => <<"special value!">> }}.
observe_rsc_update(#rsc_update{action = insert, id = Id}, {error, _} = Error, Context) ->
    Error.